Multifunctional IoT-Based Numerical Relay for Power System Protection

Abstract

Conventional relays such as electromechanical and solid-state relays, exhibit inadequate speed and flexibility, preventing their applicability in existing smart grid infrastructures. Their constrained adaptability and maintenance requirements reduce their efficiency in fluctuating power contexts. Realization of smart distribution networks demands cost-effective, adaptive, and remotely controlled protective systems. This study presents the design and development of a multifunctional numerical relay developed/working on the concept of IoT. The proposed relay module offers accurate fault detection and real-time monitoring. The Arduino UNO microcontroller serves as the central part of the relay, which takes voltage and current signals from a sensor and, based upon post-processed signals, detects the system status and sends the alert command to the circuit breaker. The built-in board is presented as a multifunctional numerical relay that can detect various faults, such as overcurrent, under/over voltage, under/over frequency, under impedance, and transmission short circuit fault. For testing, an LCD is interfaced with the relay to display electrical parameters and the system’s status. For remote monitoring, a cloud-based logging mechanism is implemented. The proposed relay module is validated for various faulty conditions in the laboratory environment, and accurate responses are observed. The proposed relay can be used for the protection of evolving smart grid faults with SCADA or building management system platforms. It can serve as a cost-effective power system protection solution to safeguard electrical circuits, and sensitive power electronic devices.